Front-Loading Sputum Microscopy Services: An Opportunity to Optimise Smear-Based Case Detection of Tuberculosis in High Prevalence Countries

Table 2

Yield of the third smear for samples collected using the standard (spot-morning-spot) and the front-loading (spot-spot-morning) approaches by country. 62 patients (15 from Yemen, 44 from Nepal, and 3 from Ethiopia) were excluded as they did not submit the third specimen.

Standard approach	Front-loading approach			𝑃^∗
Yemen (N = 235)	Pos on 1st two smears	Only 3rd smear pos	All negative	.14
Pos on 1st two smears	56	4	0
Only 3rd smear pos	0	0	0
All negative	0	0	175
Nepal (N = 162)				.76
Pos on 1st two smears	40	6	0
Pos on the 3rd smear	3	0	5
Negative in all	3	0	105
Nigeria (N = 224)				.61
Pos on 1st two smears	47	1	0
Pos on the 3rd smear	0	0	0
Negative in all	0	0	176
Ethiopia (N = 240)				.55
Pos on 1st two smears	46	3	0
Pos on the 3rd smear	2	0	0
Negative in all	1	0	188
All sites (N = 861)				.58
Pos on 1st two smears	189	14	0
Pos on the 3rd smear	5	0	5
Negative in all	4	0	644

^∗Stuart-MaxWell test, (Marginal Heterogeneity).